Array substrate and liquid crystal display apparatus having the same

ABSTRACT

In an array substrate and an LCD apparatus having the same, the array substrate includes a signal line, a first insulating layer formed on the signal line, and a pixel electrode formed on the first insulating layer and overlapped with the signal line. The pixel electrode is electrically connected with the signal line so as to discharge a signal through the signal line. A second insulating layer is disposed between the pixel electrode and the first insulating layer, and includes an opening formed in an overlapped area of the pixel electrode and the signal line so as to partially expose the first insulating layer. Thus, the LCD apparatus may have an enhanced display quality.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application relies for priority upon Korean PatentApplication No. 2003-21875 filed on Apr. 8, 2003, the contents of whichare herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an array substrate and a liquidcrystal display (LCD) apparatus having the same, and more particularlyto an array substrate capable of improving a display quality and an LCDapparatus having the same.

[0004] 2. Description of the Related Art

[0005] In general, an LCD apparatus includes an array substrate, a colorfilter substrate and a liquid crystal layer interposed between the arraysubstrate and the color filter substrate.

[0006] The array substrate includes a transmissive electrodeelectrically connected to a thin film transistor (referred as TFT), anda reflective electrode disposed on the transmissive electrode such thatthe transmissive electrode is partially exposed.

[0007] The color filter substrate includes a color filter, aplanarization layer and a common electrode successively formed thereon.The color filter includes red (R), green (G) and blue (B) color pixelsso as to display a predetermined color while a light passestherethrough.

[0008] In order to maximize reflection efficiency, the color filterincludes the R, G and B color pixels partially overlapped with eachother without forming a separate black matrix between the R, G and Bcolor pixels. The color filter, generally, has the planarization layerdisposed thereon so as to reduce step-difference caused between the R, Gand B color pixels of the color filter. The common electrode isuniformly formed in terms of a thickness on the planarization layer.

[0009] However, a protrusion, for example, such as a fine dust caused bya process environment or a protrusion generated by an aggregation of theplanarization layer itself, may be formed on the planarization layer.The protrusion has a size of about 1.0 μm to about 10 μm.

[0010] The protrusion formed on the planarization layer may electricallyshorts between the common electrode of the color filter substrate andthe pixel electrode of the array substrate. That is, since the commonelectrode is uniformly formed as in a thickness on the planarizationlayer, the common electrode is protruded by a height as high as theprotrusion formed on the planarization layer. As a result, the commonelectrode and the pixel electrode may be electrically shorted to eachother. Consequently, a high pixel that is a pixel of the shortoccurrence shows relatively whiter in color on a screen of the LCDapparatus. Particularly, as a cell gap is decreased, a number ofprotrusions caused by a non-uniform of the planarization layer may beincreased, thereby increasing the high pixel.

BRIEF SUMMARY OF THE INVENTION

[0011] The present invention provides an array substrate capable ofenhancing a display quality.

[0012] The present invention provides an LCD apparatus having the abovearray substrate.

[0013] In one aspect of the invention, an array substrate includes asignal line, a first insulating layer disposed on the signal line, apixel electrode disposed on the first insulating layer and a secondinsulating layer interposed between the first insulating layer and thepixel electrode.

[0014] The pixel electrode is formed on the first insulating layer to beoverlapped with the signal line, and electrically connected to thesignal line so as to discharge a signal externally provided through thesignal line. The second insulating layer includes an opening formed inthe overlapped area of the pixel electrode and the signal line so as toexpose the first insulating layer.

[0015] In another aspect of the invention, an LCD apparatus includes afirst substrate, a second substrate on which the common electrode isdisposed facing the first substrate, and a liquid crystal layerinterposed between the first and second substrates.

[0016] The first substrate includes a signal line, a first insulatinglayer disposed on the signal line, a pixel electrode formed on the firstsubstrate, overlapped with the signal line and electrically connectedwith the signal line so as to discharge a signal externally providedthrough the signal line, and a second insulating layer disposed betweenthe pixel electrode and the first insulating layer, and having anopening formed in the overlapped area of the pixel electrode and thesignal line so as to expose the first insulating layer.

[0017] According to the array substrate and the LCD apparatus having thesame, the gate line disposed on the array substrate is overlapped withthe pixel electrode disposed under the inorganic insulating layer, andelectrically connected with the pixel electrode so as to discharge asignal applied to the pixel electrode. The organic insulating layerincludes an opening through which the inorganic insulating layer. Thus,the LCD apparatus may improve a display quality thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other advantages of the present invention willbecome readily apparent by reference to the following detaileddescription when considered in conjunction with the accompanyingdrawings wherein:

[0019]FIG. 1 is a schematic plan view showing an array substrateaccording to an exemplary embodiment of the present invention;

[0020]FIG. 2 is a plan view showing a pixel of the array substrate shownin FIG. 1;

[0021]FIG. 3A is a cross-sectional view taken along the line A-A′ ofFIG. 2;

[0022]FIG. 3B is a cross-sectional view showing a gate line electricallyconnected with a transparent electrode;

[0023]FIG. 4 is a plan view showing a pixel of an array substrateaccording to another exemplary embodiment of the present invention;

[0024]FIG. 5A is a cross-sectional view showing a pixel taken along theline B-B′ of FIG. 4;

[0025]FIG. 5B is a cross-sectional view showing a gate line electricallyconnected with a reflective electrode;

[0026]FIG. 6 is a plan view showing a pixel of an array substrateaccording to another exemplary embodiment of the present invention; and

[0027]FIG. 7 is a cross-sectional view showing an LCD apparatusaccording to another exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0028]FIG. 1 is a schematic plan view showing an array substrateaccording to an exemplary embodiment, and FIG. 2 is a plan view showinga pixel of the array substrate shown in FIG. 1. In this exemplaryembodiment, the array substrate shown in FIGS. 1 and 2 may be applied toan LCD apparatus.

[0029] Referring to FIGS. 1 and 2, an array substrate 100 includes agate line GL extended in a first direction D1 and a data line DLextended in a second direction D2 that is substantially perpendicular tothe first direction D1.

[0030] A pixel area PA is defined in a matrix form on the arraysubstrate 100 when the gate line GL and the data line DL cross eachother. A thin film transistor (referred as TFT) 120 and a pixelelectrode are disposed in the pixel area PA. The TFT 120 includes a gateelectrode 121 electrically connected to the gate line GL, a sourceelectrode 125 electrically connected to the date line DL, and a drainelectrode 126 electrically connected to the pixel electrode. In thisexemplary embodiment, the array substrate 100, generally, includes aplurality of gate lines and a plurality of data lines as describedabove, and thus the array substrate 100 may be divided into a pluralityof pixel areas, and the TFT 120 and the pixel electrode are disposed ineach of the pixel areas.

[0031] The pixel electrode includes a transmissive electrode 150 and areflective electrode 160. The transmissive electrode 150 is electricallyconnected with the drain electrode 126 of the TFT 120, and thereflective electrode 160 disposed on the transmissive electrode 150 andelectrically connected with the drain electrode 126 of the TFT 120 bythe transmissive electrode 150. The reflective electrode 160 includes atransmissive window 165 so as to partially expose the transmissiveelectrode 150. Therefore, each pixel area PA is divided into areflective area RA on which the reflective electrode 160 is formed, anda transmissive area TA on which the transmissive window 165 is formed.

[0032] Referring to FIG. 2, the transmissive area TA is positioned at acorner of the pixel area PA, and the transmissive electrode 150 ispartially extended toward to the gate line GL, so that the transmissiveelectrode 150 is partially overlapped with the gate line GL. However,the pixel area PA may have various structures in case that thetransmissive area TA is partially adjacent to the gate line GL.

[0033] The transmissive electrode 150 is overlapped while beinginsulated from the gate line GL in the transmissive area TA. Thetransmissive electrode 150 may be electrically connected to the gateline GL.

[0034]FIG. 3A is a cross-sectional view taken along the A-A′ line ofFIG. 2, and FIG. 3B is a cross-sectional view showing a gate lineelectrically connected to a transparent electrode.

[0035] Referring to FIGS. 2 and 3A, the gate line GL and the gateelectrode 121 branched from the gate line GL are formed on a firstsubstrate 110. A gate insulating layer 122 comprising silicon nitride(SiNx) is deposited on the gate electrode 121 and the gate line GL in athickness of about 4000□. An active layer 123 and an ohmic contact layer124 are successively deposited on the gate insulating layer 122. Thedata line DL, the source electrode 125 branched from the data line DLand the drain electrode 126 separated from the source electrode 125 areformed on the first substrate 110, thereby completing the TFT 120 on thefirst substrate 110.

[0036] An inorganic insulating layer 120 including silicon nitride(SiNx) is deposited in a thickness of about 2000□ on the TFT 120 so asto protect the TFT 120. A first contact hole 131 is formed in theinorganic insulating layer 130 to partially expose the drain electrode126 of the TFT 120. Then, an organic insulating layer 140 includingacrylic resin is deposited in a thickness of about 2 to about 3 μm onthe inorganic insulating layer 130. A second contact hole 141corresponding to the first contact hole 131 is formed in the organicinsulating layer 140 so as to expose the drain electrode 126 of the TFT120.

[0037] The organic insulating layer 140 includes an opening 145 formedat a position corresponding to the transmissive area TA in order toexpose the inorganic insulating layer 130. The inorganic insulatinglayer 130 that covers the gate line GL is exposed through the opening145. The organic insulating layer 140 includes protrusions and recessesin the reflective area RA so as to enhance a reflection efficiency oflight and a viewing angle.

[0038] The transmissive electrode 150 including a transparent conductivematerial, for example, such as indium tin oxide (ITO) or indium zincoxide (IZO) and so on, is uniformly formed on the inorganic insulatinglayer 130 which is exposed through the organic insulating layer 140 andthe opening 145. The transmissive electrode 150 is electricallyconnected to the drain electrode 126 of the TFT through the first andsecond contact holes 131 and 141. Also, an overlapped area OA in whichthe transmissive electrode 150 is overlapped with the gate line GL isprovided at the transmissive area TA. The inorganic insulating layer 130and the gate insulating layer 122 are disposed between the transmissiveelectrode 150 and the gate line GL at the transmissive area TA.

[0039] The reflective electrode 160 including a single-layer of aluminumneodymium (AINd) or a double-layer of aluminum neodymium (AINd) andmolybdenum tungsten (MoW) is uniformly deposited in terms of a thicknesson the transmissive electrode 150. The reflective electrode 160 includesthe transmissive window 165 through which the transmissive electrode 150is exposed. The reflective electrode 160 also includes protrusions andrecesses by the fact that the organic insulating layer 140 includesprotrusions and recesses. Therefore, the reflective electrode 160 mayimprove the reflection efficiency and the viewing angle of the light.

[0040] A defective pixel such as the high pixel may be caused by aninternal deficiency or an external factor of the array substrate 100.

[0041] To prevent the high pixel, the transmissive electrode 150 may beelectrically connected with the gate line GL in the overlapped area OAas shown in FIG. 3B. That is, when a laser is irradiated onto theoverlapped area OA of the transmissive electrode 150 and the gate lineGL, the inorganic insulating layer 130 and the gate insulating layer 122are melted, so that the transmissive electrode 150 is electricallyconnected with the gate line GL. Thus, since the pixel in which the highpixel occurs may be maintained in an inactive state, thereby preventingdeterioration of the display quality.

[0042] Since the transmissive electrode 150 is electrically connectedwith the reflective electrode 160, when the transmissive electrode 150is electrically connected with the gate line GL, the reflectiveelectrode 160 is therefore electrically connected to the gate line GL.

[0043] The gate line GL outputs an on-voltage that is sufficient fordriving the TFT 120 connected to gate line GL for a predetermined periodin a frame, and then outputs an off-voltage during a remaining period ofthe frame.

[0044] When the transmissive electrode 150 and the gate line GL areelectrically connected to each other, the transmissive electrode 150 maymaintain the off-voltage during the remaining period. Thus, the LCDapparatus may prevent an operation of the defective pixel caused by thehigh pixel, thereby improving a display quality of the LCD apparatus.

[0045]FIG. 4 is a plan view showing a pixel of an array substrateaccording to another exemplary embodiment of the present invention, andFIG. 5A is a cross-sectional view taken along the line B-B′ of FIG. 4.

[0046] Referring to FIGS. 4 and 5A, an array substrate includes a gateline GL extended in a first direction D1, a data line DL extended in asecond direction D2 substantially perpendicular to the first directionD1, and a pixel area defined by the gate line GL and the data line DL.

[0047] A TFT 120, a transmissive electrode 150 and a reflectiveelectrode 160 are disposed in the pixel area. The TFT 120 includes agate electrode 121 electrically connected to the gate line GL, a sourceelectrode 125 electrically connected to the data line DL, and a drainelectrode 126 electrically connected to the transmissive electrode 150and to reflective electrode 160, respectively. The transmissiveelectrode 150 is directly and electrically connected to the drainelectrode 126. The reflective electrode 160 is disposed on thetransmissive electrode 150, and electrically connected to the drainelectrode 126 of the TFT 120 through the transmissive electrode 150. Thereflective electrode 160 includes a transmissive window 165 that ispartially opened so as to partially expose the transmissive electrode150. Thus, the pixel area is divided into a reflective area RA on whichthe reflective electrode 160 is formed and a transmissive area TAthrough which the transmissive window 165 is formed.

[0048] An overlapped area OA that the reflective electrode 160 isoverlapped with the gate line GL is provided in the reflective area RAwhile the reflective electrode 160 is insulated from the gate line GL.

[0049] As shown in FIGS. 4 and 5A, the gate line GL and the gateelectrode 121 diverged from the gate line GL are disposed on a firstsubstrate 110. A gate insulating layer 122 is formed over the gateelectrode 121 and the gate line GL. An active layer 123 and an ohmiccontact layer 124 are successively formed on the gate insulating layer122. The data line DL, the source electrode 125 diverged from the dataline DL, and the drain electrode 126 separated from the source electrode125 are formed on the first substrate 110, thereby completing the TFT120 on the first substrate 110.

[0050] An inorganic insulating layer 130 is formed on the TFT 120 so asto protect the TFT 120. The inorganic insulating layer 130 includes afirst contact hole 131 through which the drain electrode 126 of the TFT120 is exposed. Subsequently, an organic insulating layer 140 of acrylicresin is formed on the inorganic insulating layer 140. The organicinsulating layer 140 includes a second contact hole 141 formed at aposition corresponding to the first contact hole 131 so as to expose thedrain electrode 126 of the TFT 120..

[0051] Additionally, the organic insulating layer 140 further includesan opening 147, through which the inorganic insulating layer 130 isexposed, formed in the overlapped area OA.

[0052] The transmissive electrode 150 is formed on the organicinsulating layer 140 and the inorganic insulating layer 130 exposedthrough the opening 147. The transmissive electrode 150 is electricallyconnected with the drain electrode 126 of the TFT 120 through the firstand second contact holes 131 and 141.

[0053] The reflective electrode 160 having the transmissive window 165is formed on the transmissive electrode 150. The reflective electrode160 is overlapped with the gate line GL in the overlapped area OA. Thereflective electrode 160 and the gate line GL have the inorganicinsulating layer 130 and the gate insulating layer 122 disposedtherebetween.

[0054]FIG. 5B is a cross-sectional view showing the gate lineelectrically connected with the reflective electrode.

[0055] Referring to FIG. 5B, a defective pixel includes a structure thatelectrically connects the reflective electrode 160 and the gate line GLin the overlapped area OA.

[0056] In case that the high pixel is caused by an internal deficiencyor an external factor of the array substrate, a laser is irradiated ontothe overlapped area OA so as to electrically connect the reflectiveelectrode 160 to the gate line GL.

[0057] When the transmissive electrode 150 and the reflective electrode160 are electrically connected to the gate line GL, the transmissiveelectrode 150 and the reflective electrode 160 may maintain theoff-voltage. As a result, the defective pixel is kept as in an inactivestate. Thus, the LCD apparatus may prevent an operation of the defectivepixel, thereby improving a display quality of the LCD apparatus.

[0058] In FIGS. 1 to 5B, a reflective-transmissive type LCD apparatusthat includes the transmissive area TA and the reflective area RA in apixel area PA has been described. However, the structure of the pixelarea PA according to the present invention may be applied to areflective-transmissive type LCD apparatus that includes a pixel areahaving only a reflective area and an organic insulating layer disposedunder the reflective electrode 160.

[0059]FIG. 6 is a plan view showing an array substrate according toanother exemplary embodiment of the present invention.

[0060] Referring to FIG. 6, an array substrate according to anotherexemplary embodiment of the present invention includes a gate line GL, afirst data line DLn−1 and a second data line DLn that are insulated fromand crossing with the gate line GL. The first data line DLn−1 is ann−1^(st) data line, and the second data line DLn is an n^(th) data line.In this exemplary embodiment, the n is a natural number greater than orequal to 2.

[0061] The array substrate includes a first pixel area PA1 defined bythe gate line GL and the first data line DLn−1, and a second pixel areaPA2 defined by the gate line GL and the second data line DLn. A TFT 120,a transmissive electrode 150 and a reflective electrode 160 are formedin each of the first and second pixel areas PA1 and PA2. In thisexemplary embodiment, the first pixel area PA1 has a same structure asthat of the second pixel area PA2, and thus same numerals are applied tothe same structures of the first and second pixel areas PA1 and PA2.

[0062] One of the transmissive electrode 150 and the reflectiveelectrode 160 is overlapped with the gate line GL. In FIG. 6, astructure of the transmissive electrode 150 overlapped with the gateline GL has been shown.

[0063] In a first overlapped area OA1 of the first pixel area PA1, thetransmissive electrode 150 is overlapped with the gate line GL, and thetransmissive electrode 150 is also overlapped with the gate line GL in asecond overlapped area OA2 of the second pixel area PA2.

[0064] In a process for manufacturing the array substrate, thetransmissive electrode 150 formed in each of the first and second pixelareas PA1 and PA2 may be electrically connected to each other, thereflective electrode 160 formed in each of the first and second pixelareas PA1 and PA2 may be electrically connected to each other, or thetransmissive electrode 150 and the reflective electrode 160 of the firstand second pixel areas PA1 and PA2 may be electrically connected to eachother. In case that the transmissive electrode 150 and the reflectiveelectrode 160 are electrically connected to each other in the first andsecond pixel areas PA1 and PA2, same voltage may be applied to thetransmissive electrode 150 and the reflective electrode 160 formed inthe first and second pixel areas PA1 and PA2. As a result, the first andsecond pixel areas PA1 and PA2 formed on the array substrate may notnormally operate.

[0065] In case that the transmissive electrode 150 formed in the firstpixel area PA1 is electrically connected with the gate line GL while thefirst and second pixel areas PA1 and PA2 do not normally operated, theoff-voltage may be applied to the transmissive electrode 150 and thereflective electrode 160 formed in each of the first and second pixelareas PA1 and PA2.

[0066] That is, in a state when the transmissive electrode 150 or thereflective electrode 160 formed in each of the first and second pixelareas PA1 and PA2 are abnormally and electrically connected to eachother, the off-voltage may be applied to the transmissive electrode 150formed in the second pixel area PA2 by electrically connecting thetransmissive electrode 150 formed in the first pixel area PA1 to thegate line GL.

[0067] Therefore, two defective pixels in the first and second pixelareas PA1 and PA2 may not further receive the voltage, therebypreventing the defective pixels from further operating abnormally andenhancing a display quality.

[0068]FIG. 7 is a cross-sectional view showing an LCD apparatusaccording to another exemplary embodiment of the present invention.

[0069] Referring to FIG. 7, an array substrate according to anotherexemplary embodiment of the present invention includes an arraysubstrate 100, a color filter substrate 200 facing the array substrate100, and a liquid crystal layer 300 interposed between the arraysubstrate 100 and the color filter substrate 200.

[0070] The array substrate 100 includes a TFT 120, a transmissiveelectrode 150 and a reflective electrode 160 formed in a pixel areadefined by a gate line GL and a data line DL,. The transmissiveelectrode 150 is electrically connected with a drain electrode 126 ofthe TFT 120, and the reflective electrode 160 formed on the transmissiveelectrode 150 is electrically connected with the drain electrode 126 ofthe TFT 120 through the transmissive electrode 150.

[0071] The reflective electrode 160 includes a transmissive window 165through which the transmissive electrode 150 is partially exposed. Thus,the pixel area is divided into a reflective area RA on which thereflective electrode 160 is formed and a transmissive area TA on whichthe transmissive window 165 is formed.

[0072] The transmissive electrode 150 is overlapped with the gate lineGL while insulated from the gate line GL in the transmissive area TA.The transmissive electrode 150, however, may be electrically connectedwith the gate line GL.

[0073] The color filter substrate 200 includes a color filter 220, aplanarization layer 230 and a common electrode 240 successively formedon a second substrate 210.

[0074] The color filter 220 includes a red color pixel (R), a greencolor pixel (G) and a blue color pixel (B). Each of the R.G.B colorpixels is partially overlapped with an adjacent color pixel thereof.

[0075] The planarization layer 230 is formed on the color filter 220 soas to reduce a step-difference due to the R.G.B color pixels overlappedwith each other. The planarization layer 230 comprises an organic layer,for example, such as an acrylic resin of a photosensitive organicinsulating layers or polyimide. The common electrode 240 is uniformlyformed in a thickness on the planarization layer 230. The commonelectrode 240 includes a transparent conductive layer, for example, suchas ITO, IZO and so on.

[0076] As shown in FIG. 7, a protrusion 231 may be formed due to finedusts generated by a process in which the planarization layer is formedso as to reduce the step-difference of the color filter 220 oraggregation of an organic material for the planarization layer 230.Although the protrusion 231 is formed, the common electrode 240 isuniformly formed on the planarization layer 230 on which the protrusion231 is formed.

[0077] In general, a first distance d1 between the transmissiveelectrode 150 and the common electrode 240 in the transmissive area TAis greater than a second distance d2 between the reflective electrode160 and the common electrode 240 in the reflective area RA. In otherwords, the LCD apparatus 400 includes a first cell gap at thetransmissive area TA and a second cell gap at the reflective area RA.The first and second cell gaps are different from each other.

[0078] In comparison, the second cell gap in the reflective area RA isrelatively smaller than the first cell gap in the transmissive area TA,so that the common electrode 240 formed on the protrusion 231 may beshorted with the reflective electrode 160 formed on the transmissiveelectrode 150 in the reflective area RA.

[0079] When the common electrode 240 is electrically connected with thereflective electrode 160, the transmissive electrode 150 and thereflective electrode 160 may receive a voltage lower or higher than avoltage normally applied thereto. Consequently, a pixel corresponding tothe shorted area SA brightly or darkly appears on a screen of the LCDapparatus 400.

[0080] A laser is irradiated onto an overlapped area OA of thetransmissive electrode 150 and the gate line GL so as to electricallyconnect the transmissive electrode 150 with the gate line GL. Anoff-voltage is provided to the transmissive electrode 150 and thereflective 160 through the gate line GL. The pixel corresponding to theshorted area SA may be shown mostly as dark on the screen of the LCDapparatus 400, thereby enhancing a display quality of the LCD apparatus400.

[0081] In FIG. 7, the R.G.B color pixels of the color filter 220partially overlapped with each other has been shown. However, althoughnot shown in FIG. 7, the color filter 220 may have the R, G and B colorpixels spaced apart from each other by a predetermined distance and alight blocking layer (not shown) disposed between the R, G and B colorpixels.

[0082] According to the array substrate and the LCD apparatus having thearray substrate, the gate line GL formed on the array substrate isoverlapped with a pixel electrode. The inorganic insulating layer isdisposed between the gate line GL and the pixel electrode. The gate lineGL is electrically connected with the pixel electrode so as to dischargea signal applied to the pixel electrode. The organic insulating layerdisposed between the pixel electrode and the gate line GL includes anopening through which the inorganic insulating layer is exposed.

[0083] Therefore, since the organic insulating layer includes theopening formed in the overlapped area of the gate line GL and the pixelelectrode, the pixel electrode of malfunctioning may be electricallyconnected with the gate line GL.

[0084] As a voltage applied to the malfunctioning pixel electrode isdischarged through the gate line GL, the LCD apparatus may prevent anoccurrence of high pixel, thereby improving a display quality of the LCDapparatus.

[0085] Although the exemplary embodiments of the present invention havebeen described, it is understood that the present invention should notbe limited to these exemplary embodiments but various changes andmodifications can be made by one ordinary skilled in the art within thespirit and scope of the present invention as hereinafter claimed.

What is claimed is:
 1. An array substrate comprising: a signal line; afirst insulating layer formed on the signal line; a pixel electrodeformed on the first insulating layer, overlapped with the signal line,and electrically connected with the signal line so as to discharge asignal externally provided through the signal line; and a secondinsulating layer having an opening through which the first insulatinglayer is exposed in an area where the pixel electrode and the signalline are overlapped.
 2. The array substrate of claim 1, wherein thepixel electrode comprises: a transmissive electrode; and a reflectiveelectrode that is formed on the transmissive electrode, and has atransmissive window through which the transmissive electrode is exposed.3. The array substrate of claim 2, wherein the second insulating layercomprises a thickness in a reflective area on which the reflectiveelectrode is formed thicker than a thickness in a transmissive area atwhich the transmissive window is formed.
 4. The array substrate of claim3, wherein the signal line is formed on the transmissive area, andoverlapped with the transmissive electrode.
 5. The array substrate ofclaim 3, wherein the signal line is formed on the reflective area, andoverlapped with the reflective electrode.
 6. The array substrate ofclaim 3, wherein the second insulating layer comprises an organicinsulting layer of a convexo-concave structure in the reflective area.7. The array substrate of claim 1, further comprising: a gate line; adata line substantially perpendicular to the gate line; and a thin filmtransistor having a gate electrode connected to the gate line, a sourceelectrode connected to the data line, and a drain electrode connected tothe pixel electrode.
 8. The array substrate of claim 7, wherein thesignal line comprises the gate line.
 9. The array substrate of claim 7,the first insulating layer comprises: a gate insulating layer disposedon the signal line; and an inorganic insulating layer interposed betweenthe gate insulating layer and the second insulating layer.
 10. The arraysubstrate of claim 1, wherein the pixel electrode is a reflectiveelectrode.
 11. A liquid crystal display apparatus comprising: a firstsubstrate including: a signal line; a first insulating layer formed onthe signal line; a pixel electrode formed on the first insulating layer,overlapped with the signal line, and electrically connected with thesignal line so as to discharge a signal externally provided through thesignal line; and a second insulating layer having an opening throughwhich the first insulating layer is exposed in an area where the pixelelectrode and the signal line are overlapped; a second substrate thatincludes a common electrode, the second substrate facing the firstsubstrate; and a liquid crystal layer interposed between the firstsubstrate and the second substrate.
 12. The LCD apparatus of claim 11,wherein the pixel electrode comprises: a transmissive electrode; and areflective electrode disposed on the transmissive electrode, thereflective electrode having a transmissive window so as to expose thetransmissive electrode.
 13. The LCD apparatus of claim 12, wherein thesecond insulating layer comprises a first thickness in a reflective areaon which the reflective electrode is formed and a second thickness in atransmissive area at which the transmissive window is formed, and thefirst thickness is thicker than the second thickness.
 14. The LCDapparatus of claim 13, wherein a first distance between the transmissiveelectrode and the common electrode is larger than a second distancebetween the reflective electrode and the common electrode.
 15. The LCDapparatus of claim 13, wherein the signal line is overlapped with thetransmissive electrode in the transmissive area.
 16. An array substratecomprising: a substrate; a signal line formed on the substrate; a firstinsulating layer formed on the signal line; a second insulating layerformed on the first insulating layer, and having an opening throughwhich the first insulating layer is exposed at least in a positioncorresponding to the signal line; and a pixel electrode formed on asecond insulating layer so as to allow the pixel electrode to makecontact with the exposed first insulating layer through the opening thatincludes the position corresponding to the signal line.
 17. The arraysubstrate of claim 16, wherein the first insulating layer comprises acontact hole selectively formed therethrough such that the pixelelectrode and the signal line are electrically connected to each other,thereby discharging a signal applied to the pixel electrode.
 18. Thearray substrate of claim 17, wherein the pixel electrode comprises: atransmissive electrode; and a reflective electrode disposed on thetransmissive electrode, and having a transmissive window through whichthe transmissive electrode is exposed.
 19. The array substrate of claim18, wherein the signal line is formed in a transmissive area having thetransmissive window, and overlapped with the transmissive electrode. 20.The array of claim 18, wherein the signal line is formed in thereflective area, and overlapped with the reflective electrode.
 21. Thearray substrate of claim 16, wherein the pixel electrode is a reflectiveelectrode.